The present invention relates to a cooling system and condensation control system. In particular, the present invention relates to a cooling system and condensation control system for computer logic modules.
One of the factors that limit processing speed in computer systems is the generation of excessive heat at higher clock speeds. Significant gains of speed and reliability have been achieved by cooling computer logic modules down to temperatures below ambient. Unfortunately, cooling a logic module to below ambient temperatures can result in the formation of condensation, which is undesirable in a computer system.
Prior attempts at providing a cooling system for a computer module have not been satisfactory for higher-end computing applications. For example, one approach has been to remove moisture from incoming air cooled to 5xc2x0 C. This approach requires handling a tremendous amount of water, and does not prevent condensation in an application where refrigerant may be operating as cold as xe2x88x9240xc2x0 Celsius. Another approach has been to simply apply a fixed high-power heater around an evaporator unit which surrounds the logic module. In this way, the surface temperature of the logic module housing remains above the dew point. Another approach relies on enclosing the logic module in a vacuum enclosure as a means of providing effective insulation. Unfortunately, these approaches cannot adequately ensure that there will be no condensation in the evaporator housing and are therefore not sufficiently reliable.
Another problem unresolved by prior art cooling systems relates to condensation formed on the opposite side of the circuit board. This problem has limited the temperatures to which the logic module can be cooled to avoid condensation.
The above discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by a refrigeration system including an evaporator housing sealed to a first side of a circuit board containing a logic module, the evaporator housing including an evaporator block in thermal communication with the logic module. The evaporator housing further includes at least a humidity sensor for detecting a humidity within the evaporator housing. In another aspect of the invention, the refrigeration system includes a heater on a second side of the circuit board opposite the evaporator housing, the heater being in thermal communication with plated through-holes of the circuit board to maintain the circuit board above local ambient temperature. In another aspect of the invention, a source of dry pressurized air is provided into the sealed evaporator housing through a though-hole drilled directly under the logic module. In another aspect of the invention, a portion of the warm air exiting the processor cage is recirculated and caused to pass over the evaporator housing, thereby ensuring that the exterior surface of the evaporator housing is warming to above local dew point. In another aspect of the invention two or more modular, interchangeable refrigeration units are concurrently connected to the evaporator and are controlled independently, providing backup capability to ensure the reliability of the system.